I was discussing with a collegue about customers who ask for all types of things, but they're actually not sure what they want (and they don't realize they don't know what they want). I coined the following phrase to describe them:
"Many customers ask for a Swiss Army knife with all the accessories when all they really need is just a pizza."
In business (as well as the corporate world), so many times I see "clients" (whether they are external clients who have hired me or internal clients like managers or the accounting department) ask for lots of extra stuff that they think they need. They get so focused on the bells and whistles that they lose track of the purpose.
Especially when it comes to reports- people want this data added and that data aggregated and the report ends up so bloated that it's hardly usable any more to anyone. The customers ask for certain information without thinking how (or even if) that information will help them make a decision.
So when working with your clients, determine if they really need that Swiss Army knife they're asking for.